The Blue-tongued Skink Has a Heart of Gold - Animals | HowStuffWorks

Looking for a reptile to keep as a pet whose heart is as true blue as its tongue? You may want to look no further than the aptly named blue-tongued skink. According to myriad skink owners and Marisa Nagele, an educator at the Elmwood Park Zoo in Norristown, Pennsylvania, certain subspecies of blue-tongued skinks are intelligent, personable critters that even enjoy limited interaction with humans.

In the wild, blue-tongued skinks are found in the warm, sandy areas or grassy, savannah-like regions of Australia, New Guinea and Indonesia. They will often dig a burrow with their snouts or legs, or find an abandoned one to live in. They look very much like snakes with stubby legs, and Nagele says the skink uses that to its advantage.

"Skinks are a fairly harmless animal," she says. "They aren't poisonous, they don't have big teeth, they can't constrict their food or anything. So, when there are predators [like hawks] around, one of their biggest defenses is to pretend to be something a little scarier. In their case, it's a snake."

Nagele says the skink has what's called a parietal eye — a light sensing organ — on the top of its head that can tell when a shadow passes over.

Sensing a predator flying by, "[the skink will] actually tuck their tiny legs under their body," she says. "They will actively slither around very similar to a snake. They're going to stick their tongue out and try to slither their way away from predators," Nagele says.

Pretty clever, right? And then there's its tongue.

Why the Blue Tongue?

In nature, vivid colors usually mean something is highly toxic. Think poisonous tree frogs or brightly colored mushrooms. The phenomenon is called aposematism. The blue-tongued skink employs the same technique, though it's an ecological fake-out. That vibrant blue tongue looks gnarly, but it isn't poisonous at all.

"Skinks also have the ability to lose their tails and regrow them," says Nagele. "These guys, for sure, have quite a few defenses against predators."

Blue-tongued skinks grow to between 12 and 24 inches (30 and 61 centimeters) long, and that includes a pretty lengthy tail. And it's nearly impossible to tell the difference between male and female because their reproductive organs are internal, though you can get a blood test to determine the sex. Speaking of reproduction, blue-tongued skinks are ovoviviparous, which means the eggs are carried and hatched inside the female, then the live offspring are birthed — usually 10 to 15 youngsters.

"We think it's all about energy saving," says Nagele. "Laying eggs takes a toll on the animal's body; it's biologically expensive because they need to eat a lot of nutrients. When an animal is ovoviviparous, they retain the eggs and reabsorb a lot of the nutrients after they give birth. It eliminates a lot of the waste. It's an efficient way to give birth to their offspring."

Skinks also give the illusion of looking slimy, but they are far from it.

"Whenever I'm talking about skinks to children," says Nagele, "I always have children feel their fingernails because a skink's scales feel exactly like your fingernails do and that's because they're made out of the same stuff — keratin."

What Do Blue-tongued Skinks Eat?

Blue-tongued skinks are omnivores so they eat a little bit of everything — veggies and meat.

"For our skinks here at the zoo, they get a big salad," says Nagele. "And we feed them lots of insects (crickets) and the insects are often dusted with supplements and vitamins to make sure that they're getting all the extra nutrients that they need. We also feed them something called a Reptilink. It's kind of a mix of veggies and meat for them and looks like a little sausage. Our skink really loves them."

The blue-tongued skink at the Elmwood Park Zoo is named Sydney, and he's estimated to be 17 years old. In captivity, blue-tongued skinks will often live up to 20 years or even longer. Sydney is one of the animals in the zoo's educational collection, meeting the public as one of the ambassador animals.

"Sydney does lots of programming," says Nagele. "He goes out to meet lots of children and adults of all ages. We do educational programming, and we talk a lot about pet care and doing research about their habitat and things like that as well."

Do They Make Good Pets?

Nagele says that although blue-tongued skinks make great pets, she adds a caution.

"They're definitely not for a first-time pet owner," she says. "You have to pay attention to their lighting and heating requirements. If blue-tongued skinks don't get the appropriate calcium and appropriate lighting (which helps them metabolize the calcium) they can develop metabolic bone disease. They really need UV lighting to help them turn calcium into something usable to stay strong or they can develop calcium deformities and disease. Also, because they grow to 2 feet (0.6 meters) long, they really need to be kept in a very large terrarium."

But Nagele says, temperamentally, blue-tongued skinks are jolly good fellows.

"Sydney really loves to explore new places," she says. "He loves to hunt for his crickets. And although I wouldn't necessarily call it affectionate, you can build a relationship with reptiles, which I think a lot of people don't think of when you think of scaly creatures. You know, your first thought isn't, 'Oh, we can be friends and we can hang out.' But they definitely have their own unique personalities. And even though some of them may not be the cuddliest, they might not curl up with you (although some definitely do) they're a real joy to work with. You can really tell that they have a certain intelligence to them."